Effects of different growth conditions on epitaxial growth of (001) Ga 2 O 3 films by MOCVD

Abstract The β -Ga 2 O 3 epitaxial thin films were grown on (001) β -Ga 2 O 3 substrates using metalorganic chemical vapor deposition (MOCVD), and the effects of key growth parameters — including temperature, pressure, and oxygen-to-gallium ratio (O 2 /Ga) — on the crystalline quality, surface morphology, and electrical properties of the films were systematically investigated. The results show that while variations in these parameters did not alter the (001) preferential orientation of the β -Ga 2 O 3 films, they significantly influenced other properties. By optimizing the growth parameters, films with a surface roughness as low as 1.5 nm and the full width at half maximum (FWHM) of 33.7 arcsec were achieved. X-ray photoelectron spectroscopy (XPS) analysis showed that the oxygen vacancy concentration was significantly reduced under the optimized O 2 /Ga ratio of 820. Schottky barrier diodes (SBDs) were fabricated from three different β -Ga 2 O 3 films grown under distinct O 2 /Ga ratios. The SBD fabricated under the optimized O 2 /Ga ratio of 820, exhibits a low turn-on voltage of 0.5 V, low on-resistance of 0.022 mΩ⋅cm 2 , and a high forward current density of 678.16 A/cm 2 at 3 V. These results provide essential material and theoretical foundations for the development of β -Ga 2 O 3 based high-power electronic devices.